shmget fiddle, attempt to check if shared memory segment has already been allocated and if so, delete it.
shmget fiddle, attempt to check if shared memory segment has already been allocated and if so, delete it.

git-svn-id: 602a26e73ae9f2a14e2bb95676f2e137fcc39919@6574 7c0444ca-5550-0410-9008-faecdbe78eb5

dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV